Auxiliary connecting device for automatic telephone switchboards



April 7, 9 G. D. MANSFIELb 1,799,916

AUXILIARY CONNECTING DEVICE FOR AUTOMATIC TELEPHONE 'SWITCHBOARDS Filed April 25, 1929 is 2 30 3 2a Z 2 2a.: a. 4 bgfn I z ATTORNEYS Patented Apr. 7, 1931 UNITED STATES GEORGE D. MANSFIELD, OF PHILADELPHIA, PENNSYLVANIA.

AUXILIARY CONNECTING DEVICE FOR AUTOMATIc TEEErnonE SWITCHBOARDS Application filed April 23,

My invention relates to a new and useful auxiliary connecting device for automatic telephone switchboards whereby two exchanges extraneous to the switchboard may be connected to each other through the switchboard. 1

As at present generally constructed, automatic telephone switchboards permit of the connection of a plurality of inside or oflice 1 telephone extensions to any desired outside numbers and vice versa. Such switchboards, however, do not permit of the connection of an outside exchange call to another outside exchange call, as is often desired when a person calls his oflice switchboard operator from outside the office, and after talking to the desired office telephone extension, such person also desires to be immediately connected to another number which can only'be reached through an outside central exchange. Ac-

cording to the present practice, such person must generally first be disconnected from his ofiice switchboard and must put through, on whatever line he is using, a new trunk call 5 to the particular exchange number desired.

The delay and inconvenience of this practice is obvious, and the damage resulting therefrom is often serious, as in the case of stock brokers oflices, where a split second makes 9 a great difference, and where the executive can not afford the time or effort necessary to be connected to an outside number to which he must have immediate connection.

It is therefore the object of my invention 7 to provide a novel auxiliary connecting device whereby exchanges extraneous to the office private switchboard may be connected through said switchboard without interruption or delay.

To the above end, my invention consists of a casing, a series of interconnected contacts therein, there being apertures in thewall of said casing for receiving the plugs of the lines to be connected.

45 My invention further consists of the various novel features of construction and advantage hereinafter described and claimed.

For the purpose of illustrating my invention I have shown in the accompanying draw- 5 ings one form thereof which is at present pre- 1929. Serial No. 357,392.

ferred by me, since the same has been found in practice to give satisfactory and reliable results, although it is to be understood that the various instrumentalities of which my invention consists can be variously arranged and organized and that my invention is not limited to the precise arrangement and organization of the instrumentalities as herein shown and described. a

In the accompanying drawings: 1

Fig. 1, represents in perspective a diagrammatic view of an automatic switchboard provided with a novel auxiliary connecting device embodying my invention.

. Fig. 2,represents a section on line 2-2015 Fig. 4. g

Fig. 3, represents a section on line 3+3 of Fig. 4. I:

Fig. 4, .represents a section on line H of Fig. 3.

Fig. 5, represents a fragmentary view in elevation of the conventional plug used on switchboards." I Referring to the drawings, 1 designates a switchboardcomprising the front horizontal port1on2, the rear vertical portion 3, and the supporting legs 4:. 5 designates the listening head phones and 6 designates the receiver or mouthpiece. 7 designates an automatic dialing device whereby various numbers are called without the aid of a centraloflice operator. 8, 9, 10, and 11 designate the keys (of which'there are usually two rows) which serve to connect the calls being made or to ring any desired office extension telephone which is being called from the outside. 12, 13, 14, and 15 designate trunk cords, which are adapted to be plugged into the trunk line sockets 16, 17, 18, and 19 respectively. 2o, 21', 22, and 23 represent connecting cords whichareadapted to be plugged into any of the sockets 2 1, 25', 26, 27, 28, 29, 30, etc.

'31 designates a plug found at the free end of each of the trunk and connecting lines shown in Fig. 1, the same comprising the handle 82, thecontact portions 33, 34 .and 35 and the insulations 36. The parts heretofore described are conventional and operate in the usual manner.

.My' novelrauxiliary connecting device is composed of a casing 38 which is provided with the front apertures 39 and 40 for receiving the plugs 31 of the connecting cords 22 and 23. Within the casing 38 are secured the pair of brackets 42 by means of the metallic sleeves 43. The brackets 42 carry at their inner ends the insulating blocks 44 provided with reinforcing plates 45 and carrying the contact members 46, 47, and 48 secured by the screws 49 which also establish electrical contact between the contacts 48 and the brackets 42 which in turn are in electrical contact With the SlVS 43.

The inner ends 50, 51,- and 52 of the pairs of contacts 46, 47, and 48 are interconnected by the wires 53, 54, and 55. Vhen the plugs 31 are inserted into the apertures 39 and 40 of the casing 38 the contact portions 33 of the plugs 31 contact with the metallic sleeves 43 which are electrically connected through the brackets 42 and the screws 49 to the contact members 48. The contact portions 34 and 35 of the plugs 31 contact with the outer ends 56 and 57 of the contacts 46 and 47 rei spectively, so that when the plugs 31 of the cords 22 and 23 are inserted into the apertures 39 and 40 of the casing 38 the cords 22 and 23 are electrically interconnected.

The operation is as follows:

It is assumed that a person A, calling from the outside, wishes to speak with a person B in an office provided with an automatic switchboard, and that immediately upon the termination of this conversation, A wishes l to speak to C who is obtainable on another trunk or exchange number outside of the automatic switchboard. As above stated, it is now the practice for A to call B and then hang up or be disconnected entirely, and then to call G on the latters number. This entailed excessive delay and inconvenience, since any given number could only be connected to an other given number, and no number coul be connected to a third numher through the medium of second interme diary number.- By my invention, A is enabled to call B and as soon as he is through with B, A could talk to C without being disconnected and reconnected as would otherwise be necessary. Thus, suppose A, from outside the office, calls the switchboard operator on the trunk line corresponding to the socket 18. The trunk line 14 is plugged and the connecting cord 22 is plugged in the socket 26, as shown in dotted lines. In the meantime, the switchboard operator gets C on the trunk line 15 and instead of plugging the corresponding connection cord23 at 30, as shown in dotted lines in Fig. 1, (which would be the case if C wished to talk to someone in the ofiice through the switchboard) the line 23 is plugged in the aperture 40 in the casing 38, then As conversation with B through the trunk line 14 is terminated, the

operator next plugs the line 22 into the socket 39 of the casing 38, whereupon A can talk with C without interruption and without any effort on the part of A to get connected with C.

Considering the amount of time it takes i to be connected to any desired number, and applying the conditions to a practical case, it will be seen that a stock broker A, wishing to consult a client B and then to place an order with C, willbe greatly handicapped, and may acti'iallysustain a loss through delay in catching up to instantaneous changes in the prices prevailing. With my novel device, no loss of time is incurred since the transfer of the connection from B to C is instantaneous also.

It will thus be seen that I have devised a novel connecting device which imparts to automatic switchboards a very desirable function not heretofore present, and that my novel device is very inexpensive to manufacture.- It is also apparent that my novel auxiliary connecting device is durable and not subject to disorder so that no repair or upkeep expense is incurred.

My novel connecting device is further compact and portable so that a single device can be used in connection with a plurality of switchboards in succession.

I am aware that the invention may be embodied in other specific forms without oleparting from the spirit or essential attributes thereof, and I therefore desire the present embodiment to be considered in all respects as illustrative and not restrictive, reference being had to the appended claims rather than to the foregoing description to indicate the scope of the invention.

Having thus described my invention what I claim as new and desire to secure by Let ters Patent, is

1, In a device of the character stated, a casing having apertures in the front wall thereof adapted to receive the plugs of the trunk and other lines of a switchboard, metallic sleeves in said apertures, metallic brackets carried by and contacting with said sleeves, contact members carried by said brackets in insulated relation to said brackets and each other, and electrical conductors connecting the outer ends of said contact menr bers, the inner ends of said contact members being adapted to contact with the contact portions of said plugs when the latter are inserted in said apertures.

2. In a device of the character stated, a casing having apertures in the front wall thereof adapted to receive the plugs of the trunk and other lines of an automatic switchboard, metallic sleeves in said apertures, metallic brackets carried by and contacting with said sleeves, sets of contact members carried by said brackets in insulated relation to each other and to said brackets, and electrical conductors connecting the outer ends of said sets of contact members, the inner ends of said sets of contact members being adapted to contact with the contact portions of said plugs when the latter are inserted into said apertures, there being electrical contact between one contact member of each of said sets of contact members and the corresponding bracket.

GEORGE D. MANSFIELD. 

